diff --git a/README.md b/README.md
index 30c315e..e8e4282 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # mc mod wp24 flag provider
 
-## License
+## Notice
+The `auth_secret` constant in /src/main/java/ly65/wp24_flag_provider/Utils.java is only an example, and it should be changed and protect carefully to prevent flag leakage.
 
+## License
 the CC0 license